draw_arc

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full behavioral burden; it does usefully disclose the sweep direction and the radius > 0 constraint. It is silent on side effects: whether the entity is added to the active drawing, whether a missing layer is auto-created, and what happens on invalid geometry.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded one-line summary followed by a compact parameter list; every line adds information beyond the bare property names. Slight redundancy between the property names and the Args labels, but no wasted prose.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The return shape is covered by an existing output schema, so that need not be described. However, for a drawing-mutation tool with no annotations, the description omits environment context (which drawing is targeted, layer creation behavior, coordinate units) that would let an agent call it confidently.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, but the Args block documents every parameter: center accepts 2D or 3D coordinates, radius must be positive, angles are degrees, layer is optional, and color is an ACI value 1-255. Remaining gap is the unit/origin assumption for center coordinates.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Draw a circular arc') plus the defining behavioral detail (counter-clockwise, from start_angle_deg to end_angle_deg). An agent can distinguish this from draw_circle, draw_line and draw_polyline on the description alone.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to choose an arc over a polyline approximation, and no mention of prerequisites such as an active drawing or an existing layer. The reader must infer all usage conditions from the verb.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.